CC Madhya 12.150

ei līlā varṇiyāchena dāsa vṛndāvana
ataeva saṅkṣepa kari’ kariluṅ varṇana
Synonyms: 
ei līlā — this pastime; varṇiyāchena — has described; dāsa vṛndāvana — Vṛndāvana dāsa Ṭhākura; ataeva — therefore; saṅkṣepa — briefly; kari’ — doing; kariluṅ varṇana — I have described.
Translation: 
This incident has been described in detail by Vṛndāvana dāsa Ṭhākura. Therefore I have described it only in brief.
Purport: 

This is a matter of etiquette. If a previous ācārya has already written about something, there is no need to repeat it for personal sense gratification or to outdo the previous ācārya. Unless there is some definite improvement, one should not repeat.